Mr. Mark E. Van Every
District Ranger
Kawishiwi Ranger District
118 S. 4th Ave. E.
Ely, Minnesota 55731
Dear Mr. Van Every:
This document transmits the Fish and Wildlife Service=s (Service) final biological opinion based on our review of the biological assessment (BA) for the 2002 Special Use Projects, Kawishiwi Ranger District, Superior National Forest and its effects on the threatened Canada lynx (Lynx canadensis) in accordance with section 7 of the Endangered Species Act (Act) of 1973, as amended (16 U.S.C., 1531 et seq.). The December 9, 2002, Forest Service letter requesting concurrence with a “may effect but not likely to adversely affect” determination on 2002 Special Use Projects was received in our office on December 12, 2002. A complete administrative record of this consultation is on file in this office.
The District Court for the District of Columbia issued an order on December 26, 2002, that enjoins the Service from issuing any Awritten concurrence[s]@ that actions proposed by any Federal agencies Amay affect, but are not likely to adversely affect@ the Canada lynx. Until further notice, all consultations concerning effects to Canada lynx must be conducted in accordance with the direction of the Court. Specifically, any actions subject to consultation that may affect Canada lynx require formal consultation as described in 50 CFR 402.14. This requires the preparation of a biological opinion that addresses how the proposed action is expected to affect Canada lynx in order to complete the procedural requirements of section 7 of the Act.
Your BA also assessed the effects of the 2002 Special Use Projects on the gray wolf (Canis lupus), and the bald eagle (Haliaeetus leucocephalus). We concur with your determinations in the biological assessment concluding that 2002 Special Use Projects may affect, but will not likely adversely affect the federally threatened bald eagle or gray wolf. Our concurrence is based on your Recommendation, Mitigation, and Project Design Criteria that ensure closure of temporary roads after use, maintaining gates on selected roads, and notification requirement for wolf rendezvous or den sites and bald eagle nest or breeding territory. Specifically, your minimization measures include: (1) compliance with the Northern States Bald Eagle
Management Guidelines for bald eagle breeding territories; (2) compliance with the road density and accessibility threshold for Wolf Management Zones 1 and 2 as defined in the Gray Wolf Recovery Plan; and, (3) reinitiating consultation in the event that wolf rendezvous or den sites or bald eagle nest or breeding territory is discovered in the action area. These species will not be considered further in this biological opinion.
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Consultation History
On December 9, 2002, Kawishiwi District Ranger Van Every transmitted to the Twin Cities Ecological Services Field Office a BA for the 2002 Special Use Projects in the Kawishiwi
Ranger District. Included in the document were 13 Special Use Permits identified as 4007-01; 6847-01; 1075-38, 40 through 42, 44 through 46, 48, 49; 6591-02; and, 5289. These projects and the analysis provided in the Biological Assessment form the basis for this consultation.
BIOLOGICAL OPINION
DESCRIPTION OF THE PROPOSED ACTION
Temporary Road Access for Timber Harvest – The Minnesota Department of Natural Resources and Potlatch Company requested access across Federal land at various locations throughout the district. Purpose for access is to harvest several State and private corporation timber sales. Permits would be issued for temporary use for a 5-year period. Road widths are typically 20 feet wide. Roads will be closed via a berm or gate after use. Requests for access vary from year-round to winter or summer only. All proposals are to use old access routes. These old routes were previously used on a temporary basis for a three to five year period and then allowed to revegetate and some may have been further closed with an earthen berm. Ten routes totaling 3.8 miles of road would be authorized for this type of use.
Permanent Long-term (year around) Road Access to Private Property – Request is to upgrade an existing open roadbed across Federal land for ingress and egress to private property. Permits would be issued for permanent year-round access. Road widths are typically 20 feet wide. Minimal improvements would be needed. One route totaling 1.5 miles of road would be authorized for this type of use.
Road/Trail Permit Re-issuance – Two private access special use permits are scheduled to expire at the end of 2002. One permit is for a 1.25-mile ATV/snowmobile trail and the other is for a one mile all season road. Permits would be re-issued with existing terms and conditions. No change in use or access route would occur. These private, special use accesses traverse a wide variety of habitat types.
The access routes will directly impact a total of 13.21 acres of previously disturbed land. The area of proposed federal action is characterized by gently sloping ground moraine to irregular hilly terrain with localized steep ridges. Surrounding upland habitats exhibit medium density canopy trees with shrub understory and a ground cover of low-density herbaceous forbs and mosses. Some trees and berms will be removed and roadside berms and spot brushing will be necessary to make routes accessible. In addition to the area of direct impact, indirect impacts may occur on adjacent private lands that are characterized by mature stands of aspen, paper birch, balsam fir, red and jack pine, and, black and white spruce. Access to lands owned by the Minnesota Department of Natural Resources and Potlatch Company would be for purposes of timber harvest; access to other private lands would be for purposes of entry to recreational cabin sites.
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STATUS OF THE SPECIES
Species Description
The Canada lynx is a medium-sized cat distinguished from bobcats (Lynx rufus) by long tufts on their ears and a short, black-tipped tail (McCord and Cardoza 1982). The lynx’s long legs and large, well-furred paws make it highly adapted for hunting in deep snow. Critical habitat has not yet been designated for the threatened population of Canada lynx in the contiguous United States.
Life History
Lynx home range sizes vary from 8 to 800 square kilometers (3 to 300 square miles) and may generally be larger at the southern extent of their range (Saunders 1963; Brand et al. 1976; Mech 1980; Parker et al. 1983; Koehler and Aubry 1994; Apps 2000; Mowat et al. 2000; Squires and Laurion 2000). Lynx are capable of dispersing extremely long distances (Mech 1977; Washington Department of Wildlife 1993), and dispersal peaks when snowshoe hare (Lepus americanus) populations decline (Ward and Krebs 1985; Koehler and Aubry 1994; O’Donoghue et al. 1997; Poole 1997).
Snowshoe hares are the primary prey of lynx especially in the winter, comprising 35-97 percent of the diet throughout the range of the lynx (Koehler and Aubry 1994). Other prey species include red squirrel (Tamiasciurus hudsonicus), other small mammals and birds; lynx also eat carrion (Saunders 1963; van Zyll de Jong 1966; Nellis et al. 1972; Brand et al. 1976; Brand and Keith 1979; Koehler 1990; Staples 1995; O’Donoghue et al. 1998a, b). In northern regions, when hare densities decline, the lower quality diet causes sudden decreases in the productivity of adult female lynx and decreased survival of kittens, which causes the numbers of breeding lynx to level off or decrease (Nellis et al. 1972; Brand et al. 1976; Brand and Keith 1979; Poole 1994; Slough and Mowat 1996; O’Donoghue et al. 1997). Relative densities of snowshoe hares at southern latitudes are generally lower than those in the north, but population dynamics of southern populations of snowshoe hare are poorly understood (Hodges 2000b).
Lynx populations are closely tied to snowshoe hare distribution. Snowshoe hares have evolved to survive in areas that receive deep snow (Bittner and Rongstad 1982). They prefer stands of conifers with shrub understories that provide forage, cover to escape predators, and protection during extreme weather (Wolfe et al. 1982; Monthey 1986; Koehler and Aubrey 1994). Early
successional forest stages generally have greater understory structure than do mature forests and therefore support higher hare densities (Hodges 2000a, b), although openings in mature forests with dense understory also support hares (Buskirk et al. 2000a).
Cover is important to lynx when searching for food (Brand et al. 1976), although lynx often hunt along edges (Mowat et al. 2000). Lynx use large woody debris, such as downed logs, root wads, and windfalls, to provide denning sites with security and thermal cover for kittens (McCord and Cardoza 1982; Koehler 1990; Koehler and Brittell 1990; Mowat et al. 2000; Squires and Laurion 2000). Den sites may be located within older regenerating stands (>20 years since disturbance) or in mature conifer or mixed coniferdeciduous (typically spruce/fir or spruce/birch) forests (Mowat et al. 2000). Downed logs and overhead cover must be available throughout the home range to provide alternative den and nursery sites, and security when lynx kittens are old enough to travel (Bailey 1974). Denning habitat must also be in or near foraging habitat.
Lynx breed in spring and produce up to five kittens per litter, with litter size affected by hare densities. During the low phase of the hare cycle, few if any live kittens are born (Brand and Keith 1979; Poole 1994; Slough and Mowat 1996). Litter sizes may be smaller in southern lynx range due to lower peak hare densities (Koehler 1990; Squires and Laurion 2000).
The most commonly reported causes of lynx mortality include starvation of kittens (Quinn and Parker 1987; Koehler 1990), and human-caused mortality, mostly fur trapping (Ward and Krebs 1985; Bailey et al. 1986). Significant lynx mortality due to starvation (up to two-thirds of deaths) has been demonstrated in cyclic populations of the northern taiga, during the first 2 years of hare scarcity (Poole 1994; Slough and Mowat 1996). Other forms of mortality include predation and highway collisions, although their significance to lynx populations is unknown (Brand and Keith 1979; Carbyn and Patriquin 1983; Ward and Krebs 1985; Bailey et al. 1986).
Buskirk et al. (2000a) suggested that when other hare predators, particularly coyotes (Canis latrans), can access lynx winter hunting areas via compacted snow they may compete for prey sufficiently to affect local lynx populations. Buskirk et al. (2000a) also suggested that direct killing by coyotes, bobcats, and mountain lions (Puma concolor) could affect lynx numbers where these competitors overlap substantially with lynx.
In Canada and Alaska, lynx populations undergo extreme fluctuations in response to snowshoe hare population cycles (Mowat et al. 2000). A lack of accurate data limits our understanding of lynx population dynamics in the contiguous United States at the southern periphery of their boreal forest range. Southern lynx populations may be naturally limited by the availability of snowshoe hares, as suggested by large home range size, high kitten mortality due to starvation, and greater reliance on alternate prey.
Status and Distribution
Canada lynx range is closely associated with the distribution of North American boreal forest inhabited by snowshoe hares (Agee 2000) and extends from Alaska, the Yukon and Northwest Territories south across the United States border in the Cascades Range and northern Rocky Mountain Range, through the central Canada provinces and down into the western Great Lakes region, and east to New Brunswick and Nova Scotia, Canada and south into the northeastern United States from Maine to New York (McCord and Cardoza 1982; Quinn and Parker 1987). In the western Great Lakes region, lynx range extends south from the classic boreal forest zone into the boreal/hardwood forest ecotone (Agee 2000; McKelvey et al. 2000). At its southern margins in the contiguous United States, forests with boreal features become naturally fragmented as they transition into other vegetation types and many patches cannot support resident populations of lynx and their primary prey species.
In response to the emerging awareness of the uncertain status of Canada lynx populations and habitat in the coterminous United States and the onset of the listing process, an interagency Canada lynx coordination effort was initiated in March 1998. The Service, Forest Service, Bureau of Land Management, and National Park Service have participated in this effort. Three products important to the conservation of Canada lynx on federally managed lands have been produced AThe Scientific Basis for Lynx Conservation@ (Ruggiero et al. 1999); the Lynx Conservation Assessment and Strategy (LCAS; US Forest Service 1999); and Lynx Conservation Agreements (CA) between the Service and various land management agencies. The CA will promote the conservation of Canada lynx and its habitat in the national forests and identify actions the Forest Service agrees to take to reduce or eliminate potential adverse effects or risks to Canada lynx and their habitat. The LCAS was produced in 1999 to provide a consistent and effective approach to conservation of Canada lynx on federal lands and was used as a basis for assessing the effects of the preferred alternative on Canada lynx.
Canada lynx are solitary carnivores, generally occurring at low densities in boreal forest habitats. Within most of their range, Canada lynx densities and population dynamics are strongly tied to the distribution and abundance of snowshoe hare (Lepusamericanus), their primary prey. However, this relationship may be muted or absent in more southern populations (Halfpenny et al. 1982). Females may not reproduce during food shortages, and food availability directly correlates with the survival of young Canada lynx, with few kittens surviving when food is scarce (Koehler 1990). Kittens are born in May or June after a 60 to 74 day gestation period, and typically remain with their mothers until about 10 months of age.
Canada lynx may compete with canids, other felids, mustelids, and raptors for snowshoe hares and small mammals. Bobcat home ranges often exhibit elevational separation from those of Canada lynx, which are better adapted to deep snow. Bobcats are thought to displace Canada lynx where both felids are locally sympatric. However, Canada lynx may occasionally kill bobcats (Giddings et al. 1998).
Minnesota has a substantial number of historical lynx reports, primarily trapping records and primarily from northeastern counties (Gunderson 1978, Mech 1980, McKelvey et al. 2000). It remains unexplained how many of these records represented local residents or dispersing lynx (McKelvey et al. 2000). Historically lynx were trapped in Minnesota through both population highs and lows, indicating that at least some animals may have persisted in a core resident population. Lynx habitat in northeastern Minnesota is contiguous with boreal forest lynx habitat in Ontario and hence, the continental lynx population. Henderson (1978), Mech (1980), McKelvey et al. (2000) suggested that the harvest peaks were influenced by influxes of lynx from Canada. Harvest records for Minnesota dating back to 1930 reveal approximate 10-year cycles, with highs in Minnesota of 330-400 lynx trapped in 1940, 1952, 1962, and 1973 (John Erb, personal communication 2003).[1] Because lynx numbers did not increase in the early 1980s on the expected 10-year cycle (very few were harvested or reported observed) the lynx season was closed in 1984.
The Minnesota harvest trends are consistent with cyclical patterns in Ontario lynx harvest data. Ontario harvests were highest in 1926-27, 1962-63, and 1972-73 (Neil Dawson, personal communication 2002). Ontario harvest was then especially low in the 1990s “peak” (only one-fifth the 1972-73 harvest) following a period of very high prices for lynx pelts. The pattern of steeply declining peaks in the lynx harvest recorded from the 1970s to the 1990s in Ontario, however, occurred on a similar scale from the 1920s to the 1940s when fur prices were consistently much lower. Thus, the causes for reduced lynx harvests and likely abundance in Ontario in the early 1990s remain unexplained—as does the lack of anticipated lynx observation records in Minnesota in the early 1980s and 1990s. Snowshoe hare harvest data (the only available long-term index to hare abundance in Minnesota) show a very inconsistent pattern from 1941-2000. Hare abundance as indicated by harvests peaked in the early 1940s and 1950s along with lynx harvests, but not in the early 1950s or 1960s. In contrast, hare harvest was double any previous year from 1977-1980 yet lynx did not increase. Hares remained at relatively low densities through the 1990s. At least in recent decades, lynx dynamics in the Great Lakes region may have been influenced more by immigration than local hare cycles (McKelvey et al. 2000). The role that changes in forest disturbance patterns (fire, blowdown, timber harvest) have had on Minnesota hare populations has not been studied.
In 1999 the National Interagency Lynx Detection Protocol was initiated on two areas to determine presence of lynx at the Superior National Forest. In 2000 an additional grid was initiated in response to the Service’s Biological Opinion issued for the Superior National Forest’s Little East Creek Timber Sale. In three years of grid surveys, no lynx were detected. In February 2002 the Superior National Forest implemented lynx tracking surveys in selected areas to follow-up on increasing numbers of lynx sign and sightings. Suspected lynx hair and scat samples were collected during tracking surveys and submitted to the Rocky Mountain Research Station – Carnivore Genetics Laboratory. Laboratory results confirmed the presence of lynx in Lake, St. Louis, and Cook Counties, Minnesota. Further field collections in these selected areas confirmed multiple lynx in three areas on the Superior National Forest. A continuation of this effort through the winter may reveal the presence of lynx in new areas and provide additional data on lynx in the original survey areas. Information on confirmed lynx DNA collections and sightings